Diagnosing bleeding in cancer patients typically involves a combination of medical history, physical examination, and diagnostic tests. Blood tests, such as a complete blood count (CBC) and clotting studies, can help assess the extent of bleeding and identify underlying disorders. Imaging studies, such as CT scans or MRI, may be used to locate the source of internal bleeding. Endoscopic procedures, like colonoscopy or bronchoscopy, can be employed to visualize and diagnose bleeding in the gastrointestinal or respiratory tracts.